Shell Repair on a Furnace
Shell Repair on a Furnace
(OP)
HI All
I am planning to do a shell repair on a refractory lined furnace.
Bottom section of the furnace will have the refractory removed and shell cut out.
My concern is that do I need some kind of temporary structural support when the shell is cut out.
Mind you
- Refractory on the other part of the furnace will not be removed.
- The job should take about 3 days from cut out to replacement (excluding refractory work).
Shell thickness is 12mm, Plate is AS1548-7-430.
I have attached a sketch of equipment.
The furnace sits on a concrete support.
Any feedback or assistance is appreciated, especially from those who have done such job.

I am planning to do a shell repair on a refractory lined furnace.
Bottom section of the furnace will have the refractory removed and shell cut out.
My concern is that do I need some kind of temporary structural support when the shell is cut out.
Mind you
- Refractory on the other part of the furnace will not be removed.
- The job should take about 3 days from cut out to replacement (excluding refractory work).
Shell thickness is 12mm, Plate is AS1548-7-430.
I have attached a sketch of equipment.
The furnace sits on a concrete support.
Any feedback or assistance is appreciated, especially from those who have done such job.







RE: Shell Repair on a Furnace
RE: Shell Repair on a Furnace
Do the walls of the furnace support the refractory? My concern would be that when you cut out the wall you break the internals.
RE: Shell Repair on a Furnace
Thanks for the prompt reply.
We will break and remove the refractory inside the vessel where the shell shall be cut.
FYI, anchors are welded onto the shell to hold the refractory.
(After the new shell welded, will reinstate refractory).
I have attached another diagram below. From my understanding, the direction of movement (if any) would be towards the hole for the top section (as shown by the orange arrow).
The vessel is fully welded to the support saddle. I reckon welding two 3" sched 80 pipe with weld size of 10 (pipe to support) as stiffener should be sufficient. There is nothing I can use to support on top. The support bases are set in concrete.
What's your thought?
RE: Shell Repair on a Furnace
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RE: Shell Repair on a Furnace
The pipe connectivity close to the cut section for the stability of the vessel is necessary. You need to use the full section of the cut plate with some added margin in the selection of the pipe cross sections for the short term repair since the load path is going to change. The eccentricity that you will introduce will cause bending under the tension force on the pipes and saddle connections. Check the connections and pipes for this bending moment as well. For more detail you can check Zick analysis for pressure vessels for the available bending moment on the center cross section in the original position before cut, and figure out the tensile load on pipes and additional bending moment due to eccentricity.
You can drop the cut plate on the pipe slowly (additional weight load on pipe which will cause more additional bending on pipes) and slide the cut plate side way and remove. Do exactly opposite for the new plate, lift in place and weld.
RE: Shell Repair on a Furnace
RE: Shell Repair on a Furnace
RE: Shell Repair on a Furnace
RE: Shell Repair on a Furnace